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<head><meta charset="utf-8"><title>what is perf.rlo measuring? · t-compiler · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/index.html">t-compiler</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html">what is perf.rlo measuring?</a></h3>

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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162610369" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> pnkfelix <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162610369">(Apr 05 2019 at 10:26)</a>:</h4>
<p>Okay, I'm sorry to admit that I don't immediately remember the answer to this question ...</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162610379" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> pnkfelix <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162610379">(Apr 05 2019 at 10:26)</a>:</h4>
<p>(but I also don't feel <em>that</em> bad, since I think this information should be more apparent in the presentation itself)</p>



<a name="162610385"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162610385" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> pnkfelix <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162610385">(Apr 05 2019 at 10:26)</a>:</h4>
<p>... but: Is perf.rlo measuring the performance of the generated object binary? Or is it measuring the compilation time?</p>



<a name="162610392"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162610392" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> pnkfelix <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162610392">(Apr 05 2019 at 10:27)</a>:</h4>
<p>I'm looking in particular at stats like <a href="https://perf.rust-lang.org/compare.html?start=eab3eb38df8dca99110b6149b3a15deeb4ef0413&amp;end=4cb14446465d8d3cabfb3706f424a2938628b9f6&amp;stat=wall-time" target="_blank" title="https://perf.rust-lang.org/compare.html?start=eab3eb38df8dca99110b6149b3a15deeb4ef0413&amp;end=4cb14446465d8d3cabfb3706f424a2938628b9f6&amp;stat=wall-time">https://perf.rust-lang.org/compare.html?start=eab3eb38df8dca99110b6149b3a15deeb4ef0413&amp;end=4cb14446465d8d3cabfb3706f424a2938628b9f6&amp;stat=wall-time</a></p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162610424" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Zoxc <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162610424">(Apr 05 2019 at 10:27)</a>:</h4>
<p>It's all compilation time</p>



<a name="162610431"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162610431" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> pnkfelix <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162610431">(Apr 05 2019 at 10:27)</a>:</h4>
<p>of a bootstrapped compiler?</p>



<a name="162610436"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162610436" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Zoxc <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162610436">(Apr 05 2019 at 10:28)</a>:</h4>
<p>Yes</p>



<a name="162610482"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162610482" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> pnkfelix <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162610482">(Apr 05 2019 at 10:28)</a>:</h4>
<p>i.e.when we use perf to measure performance of a change like <a href="https://github.com/rust-lang/rust/issues/59546" target="_blank" title="https://github.com/rust-lang/rust/issues/59546">#59546</a></p>



<a name="162610487"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162610487" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> pnkfelix <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162610487">(Apr 05 2019 at 10:28)</a>:</h4>
<p>It would not surprise me if compilation took longer</p>



<a name="162610498"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162610498" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> pnkfelix <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162610498">(Apr 05 2019 at 10:28)</a>:</h4>
<p>since e.g. the compiler may be working harder to try to optimize the code in question</p>



<a name="162610519"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162610519" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> pnkfelix <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162610519">(Apr 05 2019 at 10:29)</a>:</h4>
<p>the more important thing for me to know about a case like that is "how did the object code performance change?"</p>



<a name="162610537"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162610537" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> pnkfelix <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162610537">(Apr 05 2019 at 10:29)</a>:</h4>
<p>(am I not looking at this problem the right way?)</p>



<a name="162610550"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162610550" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Zoxc <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162610550">(Apr 05 2019 at 10:29)</a>:</h4>
<p>Then <a href="https://github.com/anp/lolbench" target="_blank" title="https://github.com/anp/lolbench">https://github.com/anp/lolbench</a> is for you</p>



<a name="162610578"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162610578" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> pnkfelix <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162610578">(Apr 05 2019 at 10:29)</a>:</h4>
<p>okay, and we should be striving to integrate that with <code>@rust-timer</code> in some way?</p>



<a name="162611036"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162611036" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Zoxc <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162611036">(Apr 05 2019 at 10:36)</a>:</h4>
<p>Probably</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/what%20is%20perf.rlo%20measuring%3F/near/162614872" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> simulacrum <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/what.20is.20perf.2Erlo.20measuring.3F.html#162614872">(Apr 05 2019 at 11:45)</a>:</h4>
<p>(lolbench is pretty separate though so that might be long-term)</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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